Cutaneous Phaeohyphomycosis of the Right Hand Caused by Exophiala jeanselmei: A Case Report and Literature Review

Abstract

Exophiala spp. is increasingly reported as a pathogen causing the cutaneous, subcutaneous or invasive infection. In this report, we present a case of cutaneous phaeohyphomycosis due to E. jeanselmei on the right hand of a farmer, who suffered from this disease three years ago which had not been definitely diagnosed until he was admitted to our hospital. In our hospital, a potential fungal pathogen was observed by histopathological examination, and then was recovered and identified as E. jeanselmei by sequencing its internal transcribed spacer region. After 4 weeks of antifungal treatment, his hand recovered very well. To investigate the in vitro susceptibility of E. jeanselmei isolates to antifungal agents and compare the characteristics of their related infections among immunocompetent and immunocompromised patients, we reviewed 84 cases published in PubMed database between 1980 and 2020.

utaneous verrucose phaeohyphomycosis due to Exophiala oligosperma in an immunocompetent host

“…The patient received amphotericin B treatment after diagnosis and was cured after ten months. Another eight cases of E. oligosperma infection were reported between 2007 and 2016 and showed global distribution, including Japan, Spain, India, and Taiwan [4,[13][14][15][16]. Most of the patients had immunosuppression status.…”

“…Infection occurs primarily due to traumatic inoculation of a saprobic fungus into subcutaneous tissue. In immunocompetent individuals, the disease progresses slowly from an encapsulated cyst to a swelling without ulceration [4,5].…”

Trauma-Induced Phaeohyphomycosis in an Immunocompetent Host on Dupilumab

“…Phaeohyphomycosis is a rare infection caused by a variety of dematiaceous fungi containing melanin in their cell wall [ 1 , 3 ]. While prevalence is unknown, cases seen in immunocompromised hosts have increased in recent years [ 1 ].…”

“…Fontana-Masson stain may also be used to confirm the presence of melanin [ 1 ]. The pathogenesis of phaeohyphomycosis is usually secondary to direct inoculation from local trauma [ 1 , 3 ]. Melanin in the fungal cell wall scavenges free radicals produced by phagocytic cells, acting as the key virulence factor to make infection in immunocompetent hosts possible [ 1 , 4 ].…”

“…Antifungal therapy in combination with surgical excision is recommended for managing local phaeohyphomycosis with itraconazole considered the standard therapy even in cases of incomplete resection or relapse [ 1 , 3 , 4 ]. Our patient was started on fluconazole after insurance denied itraconazole coverage.…”